10.04.4 regression, LAN connection

[Hammi]

Hi,

I know this post is one of the worst one can make, because I'm having a problem, but don't know exactly what it is... But maybe someone can help me understand how I could investigate this....

I have a 10.04.4 machine which is connected via LAN to a DSL modem. That machine is also a host for two 10.04.4 guests (one 32 bit, one 64 bit), running various servers (apache, mysql, etc.) for my little home network. The host has an IP bridge configured, so that the guets can be reached via IP.

What happens: Since I installed one of the latest updates available via apt, the IP connection (which was rock stable before) becomes malfunctioning after a couple of days. The LAN link is not dropped, but I cannot connect any address on the internet anymore (incl. with ping) something" until I reboot the host...

Does anyone have a clue where I could start looking for the root cause, i.e. which service is failing? There is no error message in the syslog from the time when the problems start occurring...

Thanks...!

[Hammi]

Ok, I had the error again today.

I tried

• removing the bridge
• /etc/init.d/networking restart
• ifconfig up/down

Nothing helped - but after a reboot, the LAN connection worked again.

Information from the time of the error, after removal of the bridge:

ifconfig:

eth0      Link encap:Ethernet  HWaddr f4:6d:04:63:b4:e2
          inet addr:192.168.1.24  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::f66d:4ff:fe63:b4e2/64 Scope:Link           UP BROADCAST RUNNING PROMISC MULTICAST  MTU:1500  Metric:1
          RX packets:22790942 errors:0 dropped:0 overruns:0 frame:0
          TX packets:26288422 errors:0 dropped:0 overruns:0 carrier:0           collisions:0 txqueuelen:1000
          RX bytes:27559042903 (27.5 GB)  TX bytes:28209745858 (28.2 GB)
          Interrupt:30 Base address:0xc000
lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:5476887 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5476887 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:904594422 (904.5 MB)  TX bytes:904594422 (904.5 MB)

ethtool

Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes:   10baseT/Half 10baseT/Full
                        100baseT/Half 100baseT/Full
                        1000baseT/Half 1000baseT/Full Supports auto-negotiation: Yes
Advertised link modes:  10baseT/Half 10baseT/Full
                        100baseT/Half 100baseT/Full
                        1000baseT/Half 1000baseT/Full
Advertised pause frame use: No
Advertised auto-negotiation: Yes
Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                     100baseT/Half 100baseT/Full
                                     1000baseT/Full
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: MII
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: pumbg
Wake-on: g
Current message level: 0x00000033 (51)
Link detected: yes

route

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     *               255.255.255.0   U     0      0        0 eth0
link-local      *               255.255.0.0     U     1000   0        0 eth0
default         192.168.1.1     0.0.0.0         UG    100    0        0 eth0

Thanks!

[jonobr]

Hi,

I just want to clarify,

When your having your issue, the main machine , not the guests, is having the issue?

If so, then I would recommend trying a methodical approach to see whats happening.


When its running, take the results of ifconfig,
make a copy of
/etc/resolv.conf
/etc/nsswitch.conf


Then when its not working, take them again and see if anything is different.

After that, when its not working, I would try to do an nslookup in the terminal

nslookup google.com

See what response you get.
If you get a returned IP address or group of them, take one and place it in your browser and see if you can get their via the IP address.

If it appears to be DNS related, you could try putting in 8.8.8.8 (google public DNS servers) as a test.


Again, all this assumes your bridge is working ok and its a problem with your host machine